Since the early 1950s, musicians have utilized various distortion techniques to alter the sound of amplified electric musical instruments, such as electric guitars, to produce distorted sounds that are typically desired for use in recording many types of music genres including pop, blues, and rock music genres. In general, such distortion techniques include, for example, overdriving preamplifiers and/or power amplifiers, creating power supply sag, causing output transformer saturation, overdriving speakers, utilizing specially designed “distortion effect” pedal devices. There are limitations to each type of distortion technique, and often the more desirous power amplifier, output transformer, and speaker distortion techniques require operating an amplifier at or near its maximum output power level for driving speakers, which results in correspondingly high sound pressure levels emanating from the speakers.
With the advent of low cost high resolution non-linear multi-track recording systems, low cost preamplifiers, inexpensive microphones and monitor systems, along with virtual instruments and effects processors, home recording has reached near epidemic levels. The ability to record music at home has created a revolution in music production. However, the use of overdriving amplifiers to achieve the desired distorted sound of amplified electric musical instruments, such as guitars, can be problematic in home environments and many other places due to the significantly high sound pressure levels that are output from the speakers, which can be disruptive and audibly annoying to nearby individuals and neighbors.
In both commercial and home recording spaces, the high sound pressure levels utilized for amplified instrument recording causes significant complexity and cost in designing and building recording studios. Various instruments and players are often recorded simultaneously on separate recording tracks and require significant if not near perfect acoustic isolation. For example, if a singer and a guitar player are recording simultaneously, then the guitar amplifier will need to be physically and acoustically isolated from the singer and the microphone. The high sound pressure level from the guitar amplifier often acoustically bleeds into the singer's microphone, making it difficult or often not possible to process the singer's voice. Thus, typical mixing effects utilized in real-time or during post recording editing and mixing (such as pitch correction with Autotune® or Melodyne®), along with the myriad of other modern effects utilized in production, will not function properly as the vocal track is essentially contaminated by the sound of the guitar amplifier. In addition, high sound pressure levels can damage certain types of microphones prohibiting their use and/or limit the placement of certain types of microphones for recording.